Chevy Tahoe Z71 - bogs down around 55 mph

egustenhoven

My wife drives this vehicle around town - no problems. Once up on the highway and around 55-60mph, the car bogs down. I can punch it and increase the speed. It almost seems like I'm loosing vacuum pressure or the tranny isn't kicking into overdrive.

Any ideas or suggestions?

Thanks.

jcardillo

I had a situation similar to what you described. In my case it turned out to be the button switched from 2 wheel drive into one of the 4 wheel drive settings.

Hopefully, it is something simple.

Best regards,
Jeff

kiawah

Check to see that you are getting enough fuel, possibly clogged fuel filter or bad fuel pump.

tjkansas

I have a 2005 Chevy Tahoe Z71, it bogs down when I accelerate to get on the highway or similar situations when I have to give it more gas than when I take off from a stop sign or stop light etc. It won't go more than 30 to 40 mph regardless how much you push on the gas and shows an indicator light that says reduced engine power. After pulling over and shutting it down and restarting it will continue like normal with a engine light illuminated for a good portion of the day but will eventually go out. My service 4-wheel light stays on as well. Is this a problem similar to what you had? I can't get it to go into 4-wheel drive either.

marinecorpsvet

I had the same trouble with my Malibu. The fix was to find the "knock" sensor on the front of the block and disconnect it. A very knowledgeable mechanic told me that this sensor is supposed to monitor the sound of the spark plugs firing and adjust the timing to optimize it. However, if your engine has a barely perceptible knock (which a lot of GM motors have), this sensor will "hear" the knock and mis-adjust the timing so as to bog the engine down on acceleration. The solution is to find this little devil and disconnect it. It is usually on the front of the engine and to disconnect it you simply have to pull the plug out of it.

P.S. in some states your vehicle inspection will fail if this sensor is unplugged so before you take your car for inspection you will have to plug the sensor back in and drive the car for several miles to get it to register on the inspection stations computer.